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<H1 ALIGN=CENTER STYLE="margin-top: 0.48cm; margin-bottom: 0.32cm"><FONT SIZE=7>Authenticated Connections</FONT></H1>
<P><BR></P>
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	<TR><TD BGCOLOR="#e2e2e2">
<PRE><IMG SRC="images/system-search.png" ALT="" WIDTH=16 HEIGHT=16 BORDER=0><I>Tools</I>
pmcd
pminfo
pmchart
pmconfig
pmdaproc
pluginviewer
saslauthd
saslpasswd2
sasldblistusers2
kadmin.local
kinit
klist</PRE></TD></TR>
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<P>This chapter of the Performance Co-Pilot tutorial covers setting up authenticated
connections between PCP collector and monitor components.
An authenticated connection is one where the PCP collector (<B>pmcd</B> and PMDAs)
is made aware of the credentials of the user running the monitor tools.
This allows the PCP collector software to perform two important functions:
<OL>
    <LI> Grant additional access, allowing potentially sensitive information to be
	 accessed by the authenticated user;
    <LI> Make access control decisions for users and groups in order to prevent
	 inappropriate access to metrics or over-subscription of server resources.
</OL>
<P>For an explanation of Performance Co-Pilot terms and acronyms, consult 
the <A HREF="glossary.html">PCP glossary</A>.</P>
<UL>
    <LI> <A HREF="#overview">Overview</A> 
    <LI> <A HREF="#unix">Local Credentials</A> 
    <LI> <A HREF="#sasl">Remote Access</A> 
    <UL>
        <LI> <A HREF="#sasldb">Using sasldb</A>
        <LI> <A HREF="#saslauthd">Using saslauthd</A>
        <LI> <A HREF="#gssapi">Kerberos (GSSAPI)</A>
    </UL>
</UL>
<P>Note: remote host authentication will often warrant the configuration of secure
connections between PCP monitors and collectors - this is covered by a separate
tutorial: <A HREF="lab.secure.html">Secure Connections</A>.</P>
<TABLE WIDTH="100%" BORDER=0 CELLPADDING=10 CELLSPACING=20>
	<TR><TD BGCOLOR="#e2e2e2" WIDTH="70%"><BR><IMG SRC="images/stepfwd_on.png" ALT="" WIDTH=16 HEIGHT=16 BORDER=0>&nbsp;&nbsp;&nbsp;Check local PCP collector installation (requires the <I>pcp-verify</I> utility):<BR>
<PRE><B>$ pcp verify --secure</B></PRE>
</TD></TR>
</TABLE>

<P><BR></P>
<TABLE WIDTH="100%" BORDER=0 CELLPADDING=0 CELLSPACING=0 BGCOLOR="#e2e2e2">
        <TR><TD WIDTH="100%" BGCOLOR="#081c59"><P ALIGN=LEFT><FONT SIZE=5 COLOR="#ffffff"><B><A NAME="overview">Overview</A></B></FONT></P></TD></TR>
</TABLE>
<P>All connections made to the PCP metrics collector daemon (<B>pmcd</B>)
are made using the PCP protocol, which is TCP/IP based.  Traditionally, no
functionality was available to identify the user making a connection between
a PCP monitor and collector.  However, as PCP evolved to be able to export
sensitive information (event trace parameters and detailed per-process
statistics, for example), it became necessary to provide such mechanisms.</P>

<P>The Performance Co-Pilot has two facilities for transfering credentials
between the monitoring and collecting components - a local-host-only facility
using Unix domain sockets, and SASL-based authentication which can be over
either IPv4 or IPv6 sockets (local or remote).</P>

<P><BR></P>
<TABLE WIDTH="100%" BORDER=0 CELLPADDING=0 CELLSPACING=0 BGCOLOR="#e2e2e2">
        <TR><TD WIDTH="100%" BGCOLOR="#081c59"><P ALIGN=LEFT><FONT SIZE=5 COLOR="#ffffff"><B><A NAME="unix">Local Credentials</A></B></FONT></P></TD></TR>
</TABLE>

<P>For local connections, there is a fast local transport mechanism
using Unix domain sockets.  These sockets provide a facility whereby the
userid and groupid of the monitor process is automatically made available
to the collector process, with no user intervention being required.</P>

<P>This will become the default localhost transport mechanism over time.
However, its use can be requested via the <I>unix:</I> host specification
(<B>-h</B> option) with all monitor tools.</P>

<P>In the following exercise, we make use of per-process metrics from the
<B>pmdaproc</B> PCP Collector agent.
This PMDA is enabled by default, and makes use of authenticated credentials
from the monitor tools to gate access to sensitive information - process
identifiers, names, arguments, and so forth.
In modern versions of PCP, this information is unavailable (PM_ERR_PERMISSION
is returned) unless the PMDA has been given user credentials.</P>

<TABLE WIDTH="100%" BORDER=0 CELLPADDING=10 CELLSPACING=20>
	<TR><TD BGCOLOR="#e2e2e2" WIDTH="70%"><BR><IMG SRC="images/stepfwd_on.png" ALT="" WIDTH=16 HEIGHT=16 BORDER=0>&nbsp;&nbsp;&nbsp;Check for support, then establish a Unix domain socket connection with automatic credentials transfer:<BR>
<PRE><B>$ <SPAN>$PCP_BINADM_DIR</SPAN>/pmconfig -L unix_domain_sockets
unix_domain_sockets=true

$ pmprobe -f -h localhost proc.fd.count
proc.fd.count -12387 No permission to perform requested operation

$ pmprobe -f -h unix: proc.fd.count
proc.fd.count 118

$ pminfo -dmt -h unix: proc.fd.count

proc.fd.count PMID: 3.51.0 [open file descriptors]
    Data Type: 32-bit unsigned int  InDom: 3.9 0xc00009
    Semantics: instant  Units: count
</B></PRE>
</TD></TR>
</TABLE>

<P>A <I>local:</I> specification is also available, which indicates that
the monitor tool should first attempt to establish a Unix domain socket
connection (with automatic credentials transfer), but failing that fall back
to the traditional socket connection style (with no credentials transfer,
unless mandated by collector or explicitly requested by the monitor user -
described later in this tutorial).</P>

<P><B>Note:</B> this facility is completely independent and separate
to the remote access facility (described later).
Therefore, it can still be used even when support for the remote
authentication facilities is unavailable or not configured.
This local facility is always enabled on platforms that support it - these
include Linux, Mac OS X and Solaris.
</P>

<P><BR></P>
<TABLE WIDTH="100%" BORDER=0 CELLPADDING=0 CELLSPACING=0 BGCOLOR="#e2e2e2">
        <TR><TD WIDTH="100%" BGCOLOR="#081c59"><P ALIGN=LEFT><FONT SIZE=5 COLOR="#ffffff"><B><A NAME="sasl">Remote Access</A></B></FONT></P></TD></TR>
</TABLE>

<P>The alternative authentication facility is the "Simple Authentication and
Security Layer" (SASL) which provides for remote authentication.
Usually this would be used with a <A HREF="lab.secure.html">secure connection</A>
to ensure sensitive information is not transmitted in the clear.</P>

<P>SASL can be configured with many different authentication mechanisms, and this
configuration is done transparently (outside of PCP, as described shortly).
This list of mechanisms can be changed via the <I>mech_list</I> entry in the
<I>/etc/sasl2/pmcd.conf</I> file, along with other critical security parameters
defining how <B>pmcd</B> should handle authentication requests.

The <I>mech_list</I> can be set to any one of the installed SASL mechanisms,
or a space-separated list of mechanisms from which the monitor tools can select.
There are also situations where it makes sense to not set <I>mech_list</I> at
all, which we will explore shortly.</P>

<P>To make use of SASL-based authentication, both monitor and collector systems
need to be capable of running the SASL code (PCP support, in particular, must
be present on each end of the connection).
As demonstrated in the following examples, we can use both the <B>pmconfig</B>
PCP command and the <B>pluginviewer</B> SASL command to interogate aspects of
the installations on each end of a connection.
The <B>pluginviewer</B> command has separate options for reporting on client
(<B>-c</B>) and server (<B>-s</B>) components of an installation.
</P>

<I><B><A NAME="sasldb">Using sasldb</A></B></I>
<P>The SASL library provides a custom authentication technique, independent
to the set of users and groups on a system, called <I>sasldb</I>.
This involves the creation of a new authentication database separate to the
native login mechanisms that a host provides.  One advantage of using it is
that it does not require any special privileges on the part of the daemon
performing authentication (<B>pmcd</B> in our case - which does not run as
a privileged process and thus typically cannot be used with the common
authentication databases, such as the <I>/etc/shadow</I> mechanism).</P>

<P>The <I>sasldb</I> approach can be used with several SASL mechanisms, and
it is commonly used to verify a SASL setup.  Here, we will configure PCP to
use <I>sasldb</I> by allowing the &quot;plain&quot; SASL mechanism to
authenticate against it.</P>

<TABLE WIDTH="100%" BORDER=0 CELLPADDING=10 CELLSPACING=20>
	<TR><TD BGCOLOR="#e2e2e2" WIDTH="70%"><BR><IMG SRC="images/stepfwd_on.png" ALT="" WIDTH=16 HEIGHT=16 BORDER=0>&nbsp;&nbsp;&nbsp;Check for support:<BR>
<PRE><B>$ <SPAN>$PCP_BINADM_DIR</SPAN>/pmconfig -L unix_domain_sockets authentication
secure_sockets=true
authentication=true

$ pluginviewer -s -m PLAIN
[...]
Plugin "plain" [loaded], 	API version: 4
	SASL mechanism: PLAIN, best SSF: 0, supports setpass: no
	security flags: NO_ANONYMOUS|PASS_CREDENTIALS
	features: WANT_CLIENT_FIRST|PROXY_AUTHENTICATION
</B></PRE>
</TD></TR>
</TABLE>

<P>Modify the <I>/etc/sasl2/pmcd.conf</I> configuration file, so that it makes
&quot;plain&quot; authentication available to PCP monitor tools, and also
to specify the location of the SASL credentials database file.</P>

<P>By default, this has been specified as <I>/etc/pcp/passwd.db</I>.
SASL commands allow this database to be manipulated - adding, listing and
deleting users, setting their passwords, and so on.</P>

<TABLE WIDTH="100%" BORDER=0 CELLPADDING=10 CELLSPACING=20>
	<TR><TD BGCOLOR="#e2e2e2" WIDTH="70%"><BR><IMG SRC="images/stepfwd_on.png" ALT="" WIDTH=16 HEIGHT=16 BORDER=0>&nbsp;&nbsp;&nbsp;Configure the SASL library:<BR>
<PRE><B># grep PCP_SASLCONF_DIR /etc/pcp.conf
PCP_SASLCONF_DIR=/etc/sasl2

# cat <SPAN>$PCP_SASLCONF_DIR</SPAN>/sasl2/pmcd.conf
mech_list: plain scram-sha-256 gssapi
sasldb_path: /etc/pcp/passwd.db
</B></PRE>
</TD></TR>
</TABLE>

<P>Next we create the database and add some users to it.
Note that requires the previous step to have been performed,
as that informs the tools about the location of the database.</P>

<TABLE WIDTH="100%" BORDER=0 CELLPADDING=10 CELLSPACING=20>
	<TR><TD BGCOLOR="#e2e2e2" WIDTH="70%"><BR><IMG SRC="images/stepfwd_on.png" ALT="" WIDTH=16 HEIGHT=16 BORDER=0>&nbsp;&nbsp;&nbsp;Administer the SASL database (add, list and disable users):<BR>
<PRE><B># saslpasswd2 -a pmcd jack
Password: xxxxxx
Again (for verification): xxxxxx

# saslpasswd2 -a pmcd jill
Password: xxxxxx
Again (for verification): xxxxxx

# sasldblistusers2 -f /etc/pcp/passwd.db
jack@server.demo.net: userPassword
jill@server.demo.net: userPassword

# saslpasswd2 -a pmcd -d jill

# $PCP_RC_DIR/pmcd restart
</B></PRE>
</TD></TR>
</TABLE>

<P>Finally, we're ready to try it out.  As we have just restarted <B>pmcd</B>
(above), its worth checking its log file - <I>$PCP_LOG_DIR/pmcd/pmcd.log</I> -
and if that is free of errors, we can attempt to authenticate.</P>

<TABLE WIDTH="100%" BORDER=0 CELLPADDING=10 CELLSPACING=20>
	<TR><TD BGCOLOR="#e2e2e2" WIDTH="70%"><BR><IMG SRC="images/stepfwd_on.png" ALT="" WIDTH=16 HEIGHT=16 BORDER=0>&nbsp;&nbsp;&nbsp;Establish an authenticated connection:<BR>
<PRE><B>$ pminfo -fmdt -h pcps://server.demo.net?method=plain proc.fd.count
Username: jack
Password: xxxxxx

proc.fd.count PMID: 3.51.0 [open file descriptors]
    Data Type: 32-bit unsigned int  InDom: 3.9 0xc00009
    Semantics: instant  Units: count
    inst [1281 or "001281 bash"] value 4
    inst [1287 or "001287 make -j 8 default_pcp"] value 5
    inst [1802 or "001802 bash"] value 4
    [...]
</B></PRE>
</TD></TR>
</TABLE>

<I><B><A NAME="saslauthd">Using saslauthd</A></B></I>
<P>The SASL mechanism configured by default on a PCP collector system is <I>sasldb</I>
which provides a basic username and password style authentication mechanism with no
reliance on external daemons, package dependencies, and so on.
Without customisation for individual users, as described above, it allows no access
and can thus be considered secure-by-default.</P>

<P>However, it is often more convenient to use the same authentication mechanism
that is used when logging in to a host (e.g. PAM on Linux and Solaris).
Because the PCP daemons run without superuser privileges, they cannot perform this
authentication themselves, and so it must be achieved using a separate, privileged
process.
SASL provides <I>saslauthd</I> for this purpose.</P>

<TABLE WIDTH="100%" BORDER=0 CELLPADDING=10 CELLSPACING=20>
	<TR><TD BGCOLOR="#e2e2e2" WIDTH="70%"><BR><IMG SRC="images/stepfwd_on.png" ALT="" WIDTH=16 HEIGHT=16 BORDER=0>&nbsp;&nbsp;&nbsp;Check for support:<BR>
<PRE><B>$ pmconfig -L secure_sockets authentication
secure_sockets=true
authentication=true

$ pluginviewer -s -m PLAIN
[...]
Plugin "plain" [loaded], 	API version: 4
	SASL mechanism: PLAIN, best SSF: 0, supports setpass: no
	security flags: NO_ANONYMOUS|PASS_CREDENTIALS
	features: WANT_CLIENT_FIRST|PROXY_AUTHENTICATION

$ ps ax | grep saslauthd
 2857 ?        Ss     0:00 /usr/sbin/saslauthd -m /var/run/saslauthd -a pam
 2858 ?        S      0:00 /usr/sbin/saslauthd -m /var/run/saslauthd -a pam
[...]
</B></PRE>
</TD></TR>
</TABLE>

<P>In this case, the SASL mechanism configuration is entirely handled by 
<I>saslauthd</I> so we simply need to ensure we pass authentication
through to the daemon - no configuration beyond that should be needed.</P>

<TABLE WIDTH="100%" BORDER=0 CELLPADDING=10 CELLSPACING=20>
	<TR><TD BGCOLOR="#e2e2e2" WIDTH="70%"><BR><IMG SRC="images/stepfwd_on.png" ALT="" WIDTH=16 HEIGHT=16 BORDER=0>&nbsp;&nbsp;&nbsp;Setup use of <I>saslauthd</I> on the PCP Collector:<BR>
<PRE><B># grep PCP_SASLCONF_DIR /etc/pcp.conf
PCP_SASLCONF_DIR=/etc/sasl2

# cat <SPAN>$PCP_SASLCONF_DIR</SPAN>/sasl2/pmcd.conf
pwcheck_method: saslauthd

# <SPAN>$PCP_RC_DIR</SPAN>/pmcd restart
</B></PRE>
</TD></TR>
</TABLE>

<P>We are now ready to establish an authenticated connection.
<I>saslauthd</I> will log into the system log, so any authorisation
failures can be further diagnosed using information captured there.</P>

<TABLE WIDTH="100%" BORDER=0 CELLPADDING=10 CELLSPACING=20>
	<TR><TD BGCOLOR="#e2e2e2" WIDTH="70%"><BR><IMG SRC="images/stepfwd_on.png" ALT="" WIDTH=16 HEIGHT=16 BORDER=0>&nbsp;&nbsp;&nbsp;Setup use of <I>saslauthd</I> on the PCP Collector:<BR>
<PRE><B>$ pminfo -h pcps://server.demo.net?method=plain -dfmt proc.fd.count
Username: jack
Password: xxxxxx

proc.fd.count PMID: 3.51.0 [open file descriptors]
    Data Type: 32-bit unsigned int  InDom: 3.9 0xc00009
    Semantics: instant  Units: count
    inst [1281 or "001281 bash"] value 4
    inst [1287 or "001287 make -j 8 default_pcp"] value 5
    inst [1802 or "001802 bash"] value 4
    [...]
</B></PRE>
</TD></TR>
</TABLE>

<I><B><A NAME="gssapi">Kerberos Authentication</A></B></I>
<P>The PCP collector system can be configured to authenticate using Kerberos
single-sign-on using the GSSAPI authentication mechanism.
This mechanism is enabled via the <I>mech_list</I> option in <I>/etc/sasl2/pmcd.conf</I>,
and the keytab should be set to <I>/etc/pcp/pmcd/krb5.tab</I>.

<TABLE WIDTH="100%" BORDER=0 CELLPADDING=10 CELLSPACING=20>
	<TR><TD BGCOLOR="#e2e2e2" WIDTH="70%"><BR><IMG SRC="images/stepfwd_on.png" ALT="" WIDTH=16 HEIGHT=16 BORDER=0>&nbsp;&nbsp;&nbsp;Check for support:<BR>
<PRE><B>$ pmconfig -L secure_sockets authentication
secure_sockets=true
authentication=true

$ pluginviewer -s -m GSSAPI
[...]
Plugin "gssapiv2" [loaded], 	API version: 4
	SASL mechanism: GSSAPI, best SSF: 56, supports setpass: no
	security flags: NO_ANONYMOUS|NO_PLAINTEXT|NO_ACTIVE|PASS_CREDENTIALS|MUTUAL_AUTH
	features: WANT_CLIENT_FIRST|PROXY_AUTHENTICATION|DONTUSE_USERPASSWD
</B></PRE>
</TD></TR>
</TABLE>

<TABLE WIDTH="100%" BORDER=0 CELLPADDING=10 CELLSPACING=20>
	<TR><TD BGCOLOR="#e2e2e2" WIDTH="70%"><BR><IMG SRC="images/stepfwd_on.png" ALT="" WIDTH=16 HEIGHT=16 BORDER=0>&nbsp;&nbsp;&nbsp;Setup Kerberos authentication on the PCP Collector:<BR>
<PRE><B># kadmin.local
kadmin.local: add_principal pmcd/server.demo.net
Enter password for principal "pmcd/server.demo.net@DEMO.NET":
Re-enter password for principal "pmcd/server.demo.net@DEMO.NET":
Principal "pmcd/server.demo.net@DEMO.NET" created.

kadmin.local:  ktadd -k /root/pmcd-server-demo.tab pmcd/server.demo.net@DEMO.NET
Entry for principal pmcd/server.demo.net@DEMO.NET with kvno 4, encryption type Triple DES cbc mode with HMAC/sha1 added to keytab WRFILE:/root/pmcd-server-demo.tab.
Entry for principal pmcd/server.demo.net@DEMO.NET with kvno 4, encryption type ArcFour with HMAC/md5 added to keytab WRFILE:/root/pmcd-server-demo.tab.
Entry for principal pmcd/server.demo.net@DEMO.NET with kvno 4, encryption type DES with HMAC/sha1 added to keytab WRFILE:/root/pmcd-server-demo.tab.
Entry for principal pmcd/server.demo.net@DEMO.NET with kvno 4, encryption type DES cbc mode with RSA-MD5 added to keytab WRFILE:/root/pmcd-server-demo.tab.

kadmin.local: quit

# scp /root/pmcd-server-demo.tab root@server.demo.net:/etc/pcp/pmcd/krb5.tab
# rm /root/pmcd-server-demo.tab

$ kinit jack@DEMO.NET
Password for jack@DEMO.NET: xxxxxx

$ klist
Ticket cache: FILE:/tmp/krb5cc_500
Default principal: jack@DEMO.NET

Valid starting     Expires            Service principal
02/07/13 20:46:40  02/08/13 06:46:40  krbtgt/DEMO.NET@DEMO.NET
	renew until 02/07/13 20:46:40

$ pminfo -h 'pcps://server.demo.net?method=gssapi' -dfmt proc.fd.count

proc.fd.count PMID: 3.51.0 [open file descriptors]
    Data Type: 32-bit unsigned int  InDom: 3.9 0xc00009
    Semantics: instant  Units: count
    inst [1281 or "001281 bash"] value 4
    inst [1287 or "001287 make -j 8 default_pcp"] value 5
    inst [1802 or "001802 bash"] value 4
    [...]
</B></PRE>
</TD></TR>
</TABLE>

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